The objective of
General Motors Engineering Development Vehicle (GM EDV) is
to develop, design, implement and investigate a subset of
technologies that will be available on the deployment
vehicles to be used in the ACAS/FOT Program. These
technologies will be evaluated on this vehicle and will go
through a down selection process with other technologies
being investigated by the partners in the program. The basic
technologies being focused on at this time on this vehicle
are:

Threat
assessment

GPS/Map based
path prediction

Evaluating the
performance of the Assistware System

Human factors

These technologies
are elaborated in different sections of the report and will
also be summarized later in this section.

Approach

The GM EDV is a
2000 model year Buick LeSabre that has gone through a
significant modification to accommodate all the required
instrumentation to investigate the intended technologies.
Our approach in building this vehicle consisted of three
major steps.

Defining the
architecture - This important step consisted of
analyzing various architectures and configurations, and
finally determining the best approach for this task.
Important factors in this determination were:

simplicity and
ease of implementation

compatibility
with our partnersí architectures

ease of
debugging the system

ease of
collecting data

Implementing the
architecture in the laboratory - However well the test
vehicle is designed and built, it is still a very
cumbersome and inconvenient environment to debug a
system. For this reason, the first step taken in this
task was to implement the architecture in the
laboratory. The configuration that was intended for the
vehicle was implemented on the bench with exactly the
same computers, communications scheme, and add-on
sensors. However, integrating the vehicle sensors on the
bench system is not possible in a laboratory
environment.

Work
Accomplished

The following has
been accomplished on the GM Engineering Vehicle (EDV).

System
Hardware

The system hardware
was debugged on the bench and made operational. Initially,
rudimentary software for the functions performed by each
module was integrated with the communications software, to
make sure the communications software and processor hardware
were working properly. Then, the operation of sensors was
verified, although the data provided is not meaningful in
this environment.

Before
instrumenting the vehicle, necessary electrical and
mechanical infrastructure was built to support the system.
Electrical upgrades consist of installing a high output
alternator in addition to wiring, power and signal,
terminals, fuses and various relays. Mechanical upgrades
consist of various brackets for computers and sensors, wire
and cable routing, modifications to various parts of the
vehicle to install subsystems/devices.

The instrumentation
was installed in various parts of the vehicle. The grille
and the engine compartment contain the radar sensor. The
passenger compartment contains the yaw rate sensor,
accelerometer, and compass, which are underneath the
console. A high head down display (HHDD) is immediately in
front of the driver embedded in the dashboard. A speaker for
audio feedback is under the instrument panel and is driven
by an amplifier in the trunk. Haptic feedback, which
consists of a seat vibrator, is embedded into the driverís
seat in the lumbar area. The engineering terminal is in the
back seat immediately behind the front passenger. This
consists of a liquid crystal display and keyboard. A single
display and keyboard will support multiple computers in the
vehicle. An electronic switch box is installed in the
opening between the trunk and the passenger compartment. By
pushing the selector switch on this box, it will connect the
terminal to the next computer in round-robin fashion.

The trunk is where
the majority of the computers and devices are installed. A
number of computers with a dedicated floppy disk drive for
program loading are permanently installed. A panel with all
the signals serves the purpose of a breakout box for
observing the sensor signals. The Assistware system,
differential global positioning system (DGPS), Class 2 bus
to serial converter, and a soundboard with amplifier are all
laid out on a baseboard in the trunk. In addition, there is
a data acquisition system, which resides in the trunk but
will be used on demand in conjunction with a laptop, when
needed.

The exterior of the
vehicle is used for antennas. The antenna for the compass is
hidden in the headliner. The antenna for the DGPS of the
Assistware system and the road geometry processor are
mounted on the trunk lid. A second DGPS antenna for data
truthing in certain tests will be temporarily mounted on the
trunk lid.

EDV
Architecture

The architecture
and block diagram of the GM EDV is shown in Figure 13.1.
This architecture is being implemented and built into the
vehicle.

The backbone of the
system is a CAN bus for communicating between various
subsystems in the vehicle. The bus is operating at 500 Kbaud
rate and uses an 11-bit identification code for messages.
One end of the bus is terminated at the radar, which is at
an extreme location physically. The other end is terminated
at the Sensor and Driver I/O Processor.

There are a number
of processors that share the tasks to be accomplished.
Sensor and Driver I/O Processor is the interface between the
vehicle, the driver and the system. It is interfaced to
in-vehicle production sensors and devices. This is
accomplished via two separate paths. First is the Class 2
bus; any sensor information of use to the GM EDV on this bus
is monitored and captured. Then interface electronics
convert Class 2 messages to RS232 format. Any sensor or
device parameter not available on Class 2 bus is directly
interfaced. This information is gathered through either
discrete digital inputs or an analog to digital converter.
Non-production sensors are installed on the vehicle. These
are the differential global positioning system (DGPS),
compass, longitudinal/lateral accelerometer, steering wheel
position sensor, yaw rate sensor. The driver inputs are
captured through the steering wheel buttons. The Driver
Vehicle Interface (DVI) Unit, consists of a High Head Down
Display (HHDD), a soundboard, and seat vibrator.

The Road Geometry
Processor is used to determine the road geometry ahead of
the vehicle based on DGPS data and maps. It receives the
DGPS data periodically through the Sensor Processor and the
CAN bus. The maps are permanently stored on the hard disk
media in this processor. It generates a data record which
defines the path of the road ahead, and this information is
placed on the CAN bus to be picked up by the Main Processor.

The Main Processor
performs many functions: data fusion, path prediction,
target selection, and threat assessment. It receives the
data from the radar via the CAN bus, which contains target
tracks and additional pertinent information, related to
detected targets. It receives vehicle sensor data and road
geometry processor output for data fusion to predict the
vehicle path. Based on the radar targets and predicted path,
it selects the most threatening target. The threat
assessment algorithm(s) are performed on this target based
on the kinematics of the vehicle, which is monitored by the
sensor processor and the target, which is determined from
target information.

The radar is
directly interfaced to the CAN bus. At power up it requires
an initialization message which will be sent automatically
by the Delphi Delco Path Prediction Unit. This
initialization message configures the radar main processor
to transmit the requested data periodically, at a 10 Hz
rate.

The Delco Path
Prediction Unit, as the name implies, is a stand-alone box
which predicts the vehicle path based on vehicle dynamics
sensors. In addition, it initializes the radar to the proper
mode.

Assistware is a
forward vision system that has two functions. First, it has
a forward-looking camera and a vision processor to determine
the lane marker positions and the attitude of the vehicle
within the lane, specifically, offset from the centerline,
and the heading. Second, it has a GPS/map module which is
capable of building maps as the vehicle is driven around.

The Driver Vehicle
Interface (DVI) Unit consists of several devices that alert
the driver. A High Head Down Display (HHDD) is directly in
front of the driver on the dashboard and, displays various
graphics and icons as well as text data. The speaker
generates various tones to get the attention of the driver
under certain conditions. A seat shaker is the haptic
output, which is another mode for alerting the driver.

All processors are
connected to a switch box which enables them to share a
common monitor and keyboard. The monitor and keyboard are
mounted on the back seat for the engineer to control the
overall system. Not shown in the block diagram are floppy
disk drives for each processor. These features enable easy
debugging in the field and downloading of software to the
system.

Software
Development

An initial version
of all the software components of the Engineering
Development Vehicle has been designed and coded, and tested
in the lab. Currently it is in the process of being
installed in the Engineering Development Vehicle for testing
and data logging. The software components are:

The objective of
building the Prototype Vehicle is to integrate all the
technologies developed by the partners in the Program as a
precursor to the Pilot Vehicle and finally to the Deployment
Vehicles. This vehicle will have the full functionality as
required to support the FOT.

Approach

The Prototype
vehicle will also be a development vehicle in the sense that
all the subsystems that have been verified in a number
development vehicles will be integrated. This is not a
straightforward task, and will require significant
collaboration among the partners to complete.

The approach is
similar to that undertaken in the GM EDV, however bench
development in the laboratory will be limited because this
vehicle has Adaptive Cruise Control (ACC). The emphasis will
be on integration rather than development of individual
subsystems. In addition, this vehicle will contain a full
data acquisition system.

The software system
is designed such that most of the software components of the
Prototype Vehicle will have been installed and tested on the
Engineering Development Vehicle. The exceptions are:

Road geometry
from the Vision System

Road geometry
from Radar Scene Tracking

Driver-Vehicle
Interface with the HUD

Work Accomplished

The architecture
and block diagram of the Prototype Vehicle is shown in
Figure 13.1. This architecture will be implemented and built
into the Prototype Vehicle.

As of June 2000,
the following has been accomplished on the Prototype
Vehicle:

Obtain the
vehicle

Finalize bill of
materials

Order components
/ subsystems

Modify the brake
system (first phase)

This architecture
is an extension of the GM EDV. The major difference is the
addition of the Adaptive Cruise Control, which involves
throttle and brake control. The Driver Vehicle Interface is
different, mainly in the use of Head-up Display. In
addition, the functional mapping of tasks to hardware is
unlike the EDV because partners are delivering some of the
functions already implemented in hardware modules as black
boxes.